Treatment patterns and outcomes of 2310 patients with secondary acute myeloid leukemia: a PETHEMA registry study

Secondary acute myeloid leukemia (sAML) comprises a heterogeneous group of patients, and is associated with poor overall survival (OS). We analyze the characteristics, treatment patterns and outcomes of sAML adult patients of the Programa Español de Tratamientos en Hematología (PETHEMA) registry. Overall, 6211 (72.9%) were de novo and 2310 (27.1%) sAML, divided into myelodysplastic syndrome (MDS-AML, 44%), MDS/myeloproliferative (MDS/MPN-AML, 10%), MPN-AML (11%), therapy-related (t-AML, 25%), and antecedent neoplasia without prior chemotherapy/radiotherapy (neo-AML, 9%). Compared to de novo, sAML were older (median age 69 years old), had more ECOG ≥2 (35%) or high-risk cytogenetics (40%), less FLT3-ITD (11%) and NPM1 mutations (21%), and received less intensive chemotherapy regimens (38%) (all P<0.001). Median OS was higher in de novo than in sAML (10.9 vs 5.6 months, P<0.001); and shorter in sAML after hematologic disorder (MDS, MDS/MPN or MPN) as compared to t-AML and neo-AML (5.3 vs 6.1 vs 5.7 months, respectively, P=0.04). After intensive chemotherapy, median OS was better among de novo and neo-AML patients (17.2 and 14.6 months). No OS differences were observed after hypomethylating agents according to type of AML. sAML was as an independent adverse prognostic factor for OS. We confirm high prevalence and adverse features of sAML and we establish its independent adverse prognostic value. This study was registered at www.clinicaltrials.gov as #NCT02607059.

Molecular Progression of Myeloproliferative and Myelodysplastic/Myeloproliferative Neoplasms: A Study on Sequential Bone Marrow Biopsies

Myeloproliferative neoplasms (MPN) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) both harbor the potential to undergo myelodysplastic progression or acceleration and can transform into blast-phase MPN or MDS/MPN, a form of secondary acute myeloid leukemia (AML). Although the initiating transforming events are yet to be determined, current concepts suggest a stepwise acquisition of (additional) somatic mutations—apart from the initial driver mutations—that trigger disease evolution. In this study we molecularly analyzed paired bone marrow samples of MPN and MDS/MPN patients with known progression and compared them to a control cohort of patients with stable disease course. Cases with progression displayed from the very beginning a higher number of mutations compared to stable ones, of which mutations in five (ASXL1, DNMT3A, NRAS, SRSF2 and TP53) strongly correlated with progression and/or transformation, even if only one of these genes was mutated, and this particularly applied to MPN. TET2 mutations were found to have a higher allelic frequency than the putative driver mutation in three progressing cases (“TET2-first”), whereas two stable cases displayed a TET2-positive subclone (“TET2-second”), supporting the hypothesis that not only the sum of mutations but also their order of appearance matters in the course of disease. Our data emphasize the importance of genetic testing in MPN and MDS/MPN patients in terms of risk stratification and identification of imminent disease progression.

Quality-adjusted Time Without Symptoms of disease or Toxicity (Q-TWiST) analysis of CPX-351 versus 7 + 3 in older adults with newly diagnosed high-risk/secondary AML

Background CPX-351 (United States: Vyxeos®; Europe: Vyxeos® Liposomal), a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a synergistic 1:5 molar ratio, is approved by the US FDA and the EMA for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. In a pivotal phase 3 study that evaluated 309 patients aged 60 to 75 years with newly diagnosed high-risk/secondary acute myeloid leukemia, CPX-351 significantly improved median overall survival versus conventional 7 + 3 chemotherapy (cytarabine continuous infusion for 7 days plus daunorubicin for 3 days), with a comparable safety profile. A Quality‐adjusted Time Without Symptoms of disease or Toxicity (Q-TWiST) analysis of the phase 3 study was performed to compare survival quality between patients receiving CPX-351 versus conventional 7 + 3 after 5 years of follow-up. Methods Patients were randomized 1:1 between December 20, 2012 and November 11, 2014 to receive induction with CPX-351 or 7 + 3. Survival time for each patient was partitioned into 3 health states: TOX (time with any grade 3 or 4 toxicity or prior to remission), TWiST (time in remission without relapse or grade 3 or 4 toxicity), and REL (time after relapse). Within each treatment arm, Q-TWiST was calculated by adding the mean time spent in each health state weighted by its respective quality-of-life, represented by health utility. The relative Q-TWiST gain, calculated as the difference in Q-TWiST between treatment arms divided by the mean survival of the 7 + 3 control arm, was determined in order to evaluate results in the context of other Q-TWiST analyses. Results The relative Q-TWiST gain with CPX-351 versus 7 + 3 was 53.6% in the base case scenario and 39.8% among responding patients. Across various sensitivity analyses, the relative Q-TWiST gains for CPX-351 ranged from 48.0 to 57.6%, remaining well above the standard clinically important difference threshold of 15% for oncology. Conclusions This post hoc analysis demonstrates that CPX-351 improved quality-adjusted survival, further supporting the clinical benefit in patients with newly diagnosed high-risk/secondary acute myeloid leukemia. Trial registration This trial was registered on September 28, 2012 at www.clinicaltrials.gov as NCT01696084 (https://clinicaltrials.gov/ct2/show/NCT01696084) and is complete.

Myelodysplastic Syndromes in the Postgenomic Era and Future Perspectives for Precision Medicine

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal disorders caused by sequential accumulation of somatic driver mutations in hematopoietic stem and progenitor cells (HSPCs). MDS is characterized by ineffective hematopoiesis with cytopenia, dysplasia, inflammation, and a variable risk of transformation into secondary acute myeloid leukemia. The advent of next-generation sequencing has revolutionized our understanding of the genetic basis of the disease. Nevertheless, the biology of clonal evolution remains poorly understood, and the stochastic genetic drift with sequential accumulation of genetic hits in HSPCs is individual, highly dynamic and hardly predictable. These continuously moving genetic targets pose substantial challenges for the implementation of precision medicine, which aims to maximize efficacy with minimal toxicity of treatments. In the current postgenomic era, allogeneic hematopoietic stem cell transplantation remains the only curative option for younger and fit MDS patients. For all unfit patients, regeneration of HSPCs stays out of reach and all available therapies remain palliative, which will eventually lead to refractoriness and progression. In this review, we summarize the recent advances in our understanding of MDS pathophysiology and its impact on diagnosis, risk-assessment and disease monitoring. Moreover, we present ongoing clinical trials with targeting compounds and highlight future perspectives for precision medicine.

Cohesin mutations in myeloid malignancies

Cohesin is a multi-subunit protein complex that forms a ring-like structure around DNA. Cohesin is essential for sister chromatid cohesion, chromatin organization, transcriptional regulation and DNA damage repair, and plays a major role in dynamically shaping the genome architecture and maintaining DNA integrity. The core complex subunits STAG2, RAD21, SMC1 and SMC3, as well as its modulators PDS5A/B, WAPL and NIPBL, have been found to be recurrently mutated in hematologic and solid malignancies. These mutations are found across the full spectrum of myeloid neoplasia, including pediatric Down Syndrome-associated acute megakaryoblastic leukemia (DS-AMKL), myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and de-novo and secondary acute myeloid leukemia (AML). The mechanisms by which cohesin mutations act as drivers of clonal expansion and disease progression are still poorly understood. Recent studies have described the impact of cohesin alterations on self-renewal and differentiation of hematopoietic stem and progenitor cells (HSPC), which are associated with changes in chromatin and epigenetic state directing lineage commitment, as well as genomic integrity. Here, we will review the role of the cohesin complex in healthy and malignant hematopoiesis. We will discuss clinical implications of cohesin mutations in myeloid malignancies and discuss opportunities for therapeutic targeting.